Outcomes and complications of bipolar fusionless constructs for early-onset scoliosis: a systematic review.

Abstract

PURPOSE: Early-onset scoliosis (EOS) is a spinal deformity manifesting before age ten, often linked to neuromuscular conditions. Traditional Growing Rod (TGR) techniques, while effective, are associated with high complication rates and require frequent surgeries. Bipolar fixation techniques, which utilize ilio-sacral screws and sliding rods, have emerged as a less invasive alternative, aiming to preserve spinal growth. This systematic review evaluates the safety and efficacy of bipolar fixation in predominantly neuromuscular EOS and mixed pediatric cohorts reported in the current literature, exploring potential benefits and complications. METHODS: Following PRISMA guidelines, a comprehensive search of electronic databases up to April 2025 identified relevant studies. Terms included EOS, neuromuscular scoliosis, and bipolar fixation techniques. The MINORS score assessed the risk of bias in the studies. A meta-analysis was intentionally not performed due to probable overlap of patient cohorts across studies from the same surgical team; therefore, a structured narrative synthesis was undertaken. RESULTS: Nine studies with 629 patients were included, with a mean age at surgery of 10.7 years. The primary outcome, the percentage of Cobb angle correction, showed a mean preoperative angle of 75.1°, with postoperative angles ranging from 21.0° to 43.0° (average value of 33.3°). Complication rates, mainly mechanical failures and infections, averaged 36%. Mechanical failure rates varied, but infection rates were consistent across studies. CONCLUSION: Bipolar fixation techniques appear to offer a potential alternative for the treatment of early-onset scoliosis, particularly in neuromuscular cases. However, the current evidence is limited by low methodological quality and a strong predominance of studies from a single surgical team, often involving overlapping patient cohorts. Although the technique demonstrates satisfactory radiographic correction, the complication rate remains high, and the findings cannot yet be generalized. Robust, multicenter comparative studies are needed before definitive conclusions can be drawn regarding the safety and efficacy of this approach.